Today's computers are versatile machines capable of performing many tasks that traditionally require many separate machines. For example, general purpose personal computers are increasingly being used for playing back multimedia data, which usually require dedicated video viewing electronics, such as VCD players, DVD players, and the like. Multimedia data are often compressed for ease of transmission and storage. Substantial processing power and memory capabilities are required to decompress and render multimedia data. These requirements for multimedia playback can be taxing even for powerful personal computers.
Multimedia playback is a familiar and desirable feature of today's small handheld computers and other portable consumer electronic devices. The design of these computers places priorities on portability and economy. These priorities often result in reductions in processing power and memory capacity. Also, many of today's portable consumer electronic devices, including handheld computers, typically lack hardware audio/video acceleration. As a result, handheld computers and other portable consumer electronic devices typically offer a small fraction of the multimedia playback capabilities possessed by a typical personal computer. Still, users are increasingly demanding and expecting their portable consumer electronic devices to playback the same multimedia data that can be handled by their more powerful personal computers.
The current trends of multimedia data are to use higher frame rates and resolution to increase the quality of the playback while using more aggressive video compression methods to maintain reasonable requirements for transmission and storage of the data. Achieving smooth playback of computationally intensive multimedia data is challenging on a computer having insufficient processing power. Conventional audio/video synchronization methods do not deal adequately with this problem. In fact, these conventional methods tend to degrade the quality of the multimedia playback by dropping frames at the most inopportune moments, such as when the viewer's full attention is attracted by quick action or scene changes.
Thus, there is a need for a system that enables multimedia playback on computers with limited processing power without substantially degrading the quality of the playback.